Drug-immobilized inorganic nanoparticle

Abstract

An object of the present invention is to provide a composite of an inorganic nanoparticle with a medicinal compound (i.e., an active substance), and to provide a method for producing the inorganic nanoparticle composite, which is highly versatile and convenient. The present invention provides an active substance-immobilized inorganic nanoparticle wherein an active substance is immobilized through physical adsorption on the surface of an inorganic nanoparticle of 1 to 500 nm in average particle size.

1 . An active substance-immobilized inorganic nanoparticle wherein an active substance is immobilized through physical adsorption on the surface of an inorganic nanoparticle of 1 to 500 nm in average particle size. 
     
     
         2 . The inorganic nanoparticle of  claim 1  wherein the inorganic nanoparticle is a nanoparticle of a magnetic substance. 
     
     
         3 . The inorganic nanoparticle of  claim 1  wherein the inorganic nanoparticle is iron oxide or ferrite. 
     
     
         4 . The inorganic nanoparticle of  claim 1  wherein the active substance is immobilized through physical adsorption on the surface of the inorganic nanoparticle comprising an amino acid immobilized on the surface. 
     
     
         5 . The inorganic nanoparticle of  claim 1  wherein an amino acid is immobilized on the surface of the inorganic nanoparticle surface-modified with a compound represented by the formula R 1 —(OCH(R 2 )CH 2 ) n —O-L-X
 wherein R 1  represents an alkyl or alkenyl group having a carbon chain length between 1 and 20 inclusive or an unsubstituted phenyl group or a phenyl group substituted with an alkyl or alkoxyl group having a carbon chain length of 10 or less; R 2  represents a hydrogen atom or methyl group; n represents an integer between 1 and 20 inclusive; L represents a single bond or an alkylene group having 1 to 10 carbon atoms; and X represents a carboxylic acid group, a phosphoric acid group, a sulfonic acid group, a or boric acid group,   and the active substance is further immobilized through physical adsorption on the surface.   
     
     
         6 . A method for producing the inorganic nanoparticle of  claim 1 , which comprises irradiating, with ultrasonic waves, a mixture of an active substance with a dispersion of inorganic nanoparticles of 1 to 500 nm in average particle size. 
     
     
         7 . The method of  claim 6  wherein the time of the irradiation with ultrasonic waves is between 1 minute and 2 hours inclusive. 
     
     
         8 . The method of  claim 6  wherein the irradiation is performed with ultrasonic waves having a high-frequency output of 0.1 to 200 W. 
     
     
         9 . An inorganic nanoparticle produced by the method of  claim 6 . 
     
     
         10 . A hyperthermia agent which comprises the inorganic nanoparticle of  claim 1 . 
     
     
         11 . An MRI contrast medium which comprises the inorganic nanoparticle of  claim 1 . 
     
     
         12 . A drug delivery agent which comprises the inorganic nanoparticle of  claim 1 . 
     
     
         13 . A probe for analysis and diagnosis which comprises the inorganic nanoparticle of  claim 1 . 
     
     
         14 . A separating agent for a physiologically active substance which comprises the inorganic nanoparticle of  claim 1 . 
     
     
         15 . A method for magnetically separating and purifying a physiologically active substance, which comprises bringing the inorganic nanoparticle of the present invention into contact with a physiologically active substance. 
     
     
         16 . A hyperthermia agent which comprises the inorganic nanoparticle of  claim 9 . 
     
     
         17 . An MRI contrast medium which comprises the inorganic nanoparticle of  claim 9 . 
     
     
         18 . A drug delivery agent which comprises the inorganic nanoparticle of  claim 9 . 
     
     
         19 . A probe for analysis and diagnosis which comprises the inorganic nanoparticle of  claim 9 . 
     
     
         20 . A separating agent for a physiologically active substance which comprises the inorganic nanoparticle of  claim 9 .